Close vs. Quit

I clicked the red button to close Safari. Gone. Done. Moved on.

An hour later I opened Activity Monitor and found Safari still running. Along with six other apps I thought I'd closed. On Windows, clicking the X kills the app. On Mac, it closes the window and the app just... hangs around. Like a guest at a party who won't leave.

This is the single biggest behavioral difference between the two operating systems. It will trip you up for at least a week. Possibly forever.

What the Buttons Do

Three colored circles, top-left corner of every window:

Button	What It Does	Keyboard Shortcut
🔴 Red	Closes the window. The app keeps running.	Cmd + W
🟡 Yellow	Minimizes the window to the Dock.	Cmd + M
🟢 Green	Enters full screen (or resizes the window).	Ctrl + Cmd + F

Closing a window (Cmd + W) is not the same as quitting an app (Cmd + Q). Close removes the window. Quit actually terminates the process. This distinction doesn't exist on Windows, and my first week on Mac I was running fourteen apps without knowing it.

Why?

Apple's philosophy: apps should stay ready. Closing a window doesn't mean you're done with the app. Mail might be checking for messages. Spotify is playing music. Messages is receiving texts. Apps with no open windows sit in the Dock with a small dot underneath, quietly consuming RAM and pretending to be useful.

On Windows, closing the last window kills the app. Clean. Simple. Done.

On Mac, closing the last window leaves a zombie process hanging in memory. Apple calls this a "feature." Windows users call it "why is my Mac using 12 GB of RAM with nothing on screen."

Both sides have a point, honestly. Background apps reopen instantly, which is nice. Background apps eating battery while doing nothing is less nice.

How to Tell What's Running

Look at the Dock. Every app with a small dot below its icon is running. No window, no visible sign, but it's there. Cmd + Tab opens the app switcher and shows everything that's currently loaded.

How to Actually Quit

• Cmd + Q: Quits the active app
• Right-click the Dock icon > Quit
• Cmd + Tab to the app, then press Q while still holding Cmd

That last one is the pro move. Cmd + Tab to cycle through apps, and without letting go of Cmd, hit Q to close the one you're on. Fast and satisfying. Like a keyboard shortcut sniper.

Windows Comparison

Action	Windows	Mac
Close window	Alt + F4 or X	Cmd + W
Quit app	Alt + F4 or X	Cmd + Q
Minimize	Win + Down	Cmd + M
See running apps	Taskbar	Dock (dot below)

Build the habit: when you're done with an app, Cmd + Q. When you just want the window gone but plan to come back, Cmd + W. Close means "I'll be right back." Quit means "we're done here." Once this clicks, it actually makes sense. I just wish someone had told me before I discovered eight apps running in the background on day three.